MP11 Advances in Bioaccumulation Assessment
Monday, 14 November 2005: 8:00 AM - 6:30 PM in Exhibit Hall

(HOW-1117-814929) Improved BCF prediction for hydrocarbons.

Stewart, Sarah¹, Meylan, William¹, Aronson, Dallas¹, Howard, Philip¹, Parkerton, Thomas², Comber, Michael³, ¹ Syracuse Research Corporation, Syracuse, NY, USA² ExxonMobil Biomedical Sciences, Inc., Annandale, NJ, USA³ ExxonMobil, Machelen, Belgium

ABSTRACT- Bioconcentration factor (BCF) data on hydrocarbons that were used to develop the BCFWIN program within the EPI Suite were reevaluated. To improve the accuracy of the database, an extensive screening of the available literature was performed. In addition, the methodology of all studies (those used previously as well as any new studies) was examined, and only studies in which the parent compound was measured directly were included. Since hydrocarbons can be biotransformed within the organism, as is commonly reported for polycyclic aromatic hydrocarbons (PAHs), total radioactivity measurements can include metabolites as well as the parent compound. The updated database contains BCF data for 80 hydrocarbons, which were then compared to their BCFWIN estimation values. Of these 80 compounds, 49 were overestimated and 31 were underestimated (21 compounds were overestimated by more than 0.5 log units and 8 compounds were underestimated by more than 0.5 log units). Specific structural classes found to have BCF values significantly lower than their estimated value include PAH compounds with four or more fused benzene rings (overestimated by an average of approximately 1.5 log units) and linear aliphatic compounds containing 12 or more carbons (overestimated by an average of approximately 0.7 log units). Simple naphthalenes and other two-member ring compounds (e.g., decahydronaphthalene, tetralin) appear to be somewhat underestimated by the BCFWIN program (by approximately 0.65 log units).

Key words: Bioconcentration, Hydrocarbon, QSAR